The enzyme is useful for the determination of ammonia and ATP in clinical analysis.
| Origin | microorganism |
|---|---|
| Systematic name | L-Glutamate : ammonia ligase (ADP-forming) |
| EC Number | 6.3.1.2 |
| Reaction formula | ATP + L-Glutamate + NH3→→→ ADP + Orthophosphate + L-Glutamine |
| Appearance | white to light yellow lyophilizate | |
|---|---|---|
| Activity | ≧15.0 U/mg | |
| Contaminants | Catalase ≦0.5 U/U％ | |
| Stabilizer | sucrose | |
| Storage condition | below-20℃ |
| Molecular weight | ca. 900 kDa (gel filtration) |
|---|---|
| Structure | 57 kDa (SDS-PAGE) |
| Isoelectric point | 6.5 |
| Michaelis constant | 1.5×10-2M (L-glutamate) |
| 1.3×10-4M (ammonia) | |
| 8.7×10-4M (ATP) | |
| pH Optimum | ca. 7.0 |
| pH Stability | 6.5–9.5 |
| Optimum temperature | 60℃ |
| Thermal stability | below 40℃ |
| Inhibitors | methionine sulfoximine, carbamyl phosphate |
| Activators | Mg2+，Mn2+ |
| Specificity | L-glutamate (100), D-glutamate (0.8) |
| NH₃(100), NH₂OH (12) | |
| ATP (100), GTP (2.5) |
The enzyme is useful for the determination of ammonia and ATP in clinical analysis.
Ebner, E. et al., “Methods in Enzymology,” Vol. 17A, Academic Press, New York, 1970, pp. 910–922.
